To those of you who understand basis in property, I say (with an ode to AC/DC) I SALUTE YOU !!!
Example: I buy an amplifier for $5,000.00 and I pay 6% sales tax, My basis in the amp is $5,300.00. I sell it 2 years later for $3,300.00--I am selling it for a loss. The buyer has to pay tax depending on his/her jurisdiction, but I have no tax liability.
The 1099-K you may receive is only an indicia of what you received/transacted, not a precursor that automatically invokes a taxable event.
Technically, this has always been the law, it’s just the government lagged behind in updating existing laws to reflect online commerce. So I bid you all adieu, into the wild blue........